Current through Reg. 49, No. 52; December 27, 2024
(a) Application.
The general criteria set forth in this section apply to surface water in the
state and specifically apply to substances attributed to waste discharges or
human activities. General criteria do not apply to those instances when surface
water, as a result of natural phenomena, exhibit characteristics beyond the
limits established by this section. General criteria are superseded by specific
exemptions stated in this section or in §
307.8 of
this title (relating to the Application of Standards), or by site-specific
water quality standards for classified segments. Provisions of the general
criteria remain in effect in mixing zones or below critical low-flow conditions
unless specifically exempted in §
307.8 of
this title.
(b) Aesthetic
parameters.
(1) Concentrations of taste and
odor producing substances must not interfere with the production of potable
water by reasonable water treatment methods, impart unpalatable flavor to food
fish including shellfish, result in offensive odors arising from the waters, or
otherwise interfere with the reasonable use of the water in the
state.
(2) Surface water must be
essentially free of floating debris and suspended solids that are conducive to
producing adverse responses in aquatic organisms or putrescible sludge deposits
or sediment layers that adversely affect benthic biota or any lawful
uses.
(3) Surface waters must be
essentially free of settleable solids conducive to changes in flow
characteristics of stream channels or the untimely filling of surface water in
the state. This provision does not prohibit dredge and fill activities that are
permitted in accordance with the Federal Clean Water Act.
(4) Surface waters must be maintained in an
aesthetically attractive condition.
(5) Waste discharges must not cause
substantial and persistent changes from ambient conditions of turbidity or
color.
(6) No foaming or frothing
of a persistent nature is permissible.
(7) Surface waters must be maintained so that
oil, grease, or related residue do not produce a visible film or sheen of oil
or globules of grease on the surface or coat the banks or bottoms of the
watercourse; or cause toxicity to man, aquatic life, or terrestrial life in
accordance with subsection (d) of this section.
(8) There shall be no discharge of visible
pre-production plastic. For the purposes of this paragraph, visible means able
to be seen by the naked eye without special equipment. This prohibition applies
to individual and general TPDES permit authorizations held by plastic
manufacturers, formers/molders, and facilities that otherwise handle
pre-production plastic. Facilities that handle pre-production plastic must
implement best management practices as defined in §307.3(a)(7) to eliminate
discharges of visible pre-production plastic in stormwater through the
implementation of control measures such as the following, where determined
feasible (list not exclusive): minimizing spills, cleaning up spills promptly
and thoroughly, sweeping and/or vacuuming thoroughly, and pellet
capturing.
(c)
Radiological substances. Radioactive materials must not be discharged in excess
of the amount regulated by Chapter 336 of this title (relating to Radioactive
Substance Rules).
(d) Toxic
substances. Surface waters must not be toxic to man from ingestion of water,
consumption of aquatic organisms, or contact with the skin, or to terrestrial
or aquatic life. Additional requirements and criteria for toxic substances are
specified in §
307.6
of this title (relating to Toxic Materials). Criteria to protect aquatic life
from acute toxicity apply to all surface waters in the state except as
specified in §
307.8(a)(3)
of this title. Criteria to protect aquatic life from chronic toxicity apply to
surface waters with an aquatic life use of limited, intermediate, high, or
exceptional as designated in §
307.10 of this
title (relating to Appendices A - G) or as determined on a case-by-case basis
in accordance with subsection (l) of this section. Toxic criteria to protect
human health for consumption of fish apply to waters with a sustainable or
incidental fishery, as described in §
307.6(d)
of this title. Additional criteria apply to water in the state with a public
drinking water supply use, as described in §
307.6(d)
of this title. The general provisions of this subsection do not change specific
provisions in §
307.8 of
this title for applying toxic criteria.
(e) Nutrients. Nutrients from permitted
discharges or other controllable sources must not cause excessive growth of
aquatic vegetation that impairs an existing, designated, presumed, or
attainable use. Site-specific nutrient criteria, nutrient permit limitations,
or separate rules to control nutrients in individual watersheds are established
where appropriate after notice and opportunity for public participation and
proper hearing. Site-specific numeric criteria related to chlorophyll
a are listed in Appendix F of §
307.10 of this
title.
(f) Temperature. Consistent
with §
307.1 of
this title (relating to General Policy Statement) and in accordance with state
water rights permits, temperature in industrial cooling impoundments,
industrial cooling water areas, and all other surface water in the state must
be maintained so as to not interfere with the reasonable use of such waters.
Numerical temperature criteria have not been specifically established for
industrial cooling impoundments, which in most areas of the state contribute to
water conservation and water quality objectives. In addition, numerical
criteria for temperature are not applicable in designated industrial cooling
water areas, as defined in §
307.3
of this title (relating to Definitions and Abbreviations). The horizontal
boundaries of an industrial cooling water area must be defined in the
applicable wastewater permit. The following temperature criteria, expressed as
a maximum temperature differential (rise over ambient) are established except
for industrial cooling impoundments, temperature elevations due to discharges
of treated domestic (sanitary) effluent, and temperature elevations within
designated mixing zones or industrial cooling water areas. The maximum
temperature differentials are:
(1) freshwater
streams: 5 degrees Fahrenheit (degrees F);
(2) freshwater lakes and impoundments: 3
degrees F; and
(3) tidal river
reaches, bay, and gulf waters: 4 degrees F in fall, winter, and spring, and 1.5
degrees F in summer (June, July, and August).
(4) Additional temperature criteria
(expressed as maximum temperatures) for classified segments are specified in
Appendix A of §
307.10 of this
title. These criteria are not applicable within industrial cooling water
areas.
(g) Salinity.
(1) Concentrations and the relative ratios of
dissolved minerals such as chloride, sulfate, and total dissolved solids must
be maintained such that existing, designated, presumed, and attainable uses are
not impaired.
(2) Criteria for
chloride, sulfate, and total dissolved solids for classified freshwater
segments are specified in Appendix A of §
307.10 of this
title.
(3) Salinity gradients in
estuaries must be maintained to support attainable estuarine dependent aquatic
life uses. Numerical salinity criteria for Texas estuaries have not been
established because of the high natural variability of salinity in estuarine
systems, and because long-term studies by state agencies to assess estuarine
salinities are still ongoing. Absence of numerical criteria must not preclude
evaluations and regulatory actions based on estuarine salinity, and careful
consideration must be given to all activities that may detrimentally affect
salinity gradients.
(h)
Aquatic life uses and dissolved oxygen.
(1)
Dissolved oxygen concentrations must be sufficient to support existing,
designated, presumed, and attainable aquatic life uses. Aquatic-life use
categories and corresponding dissolved oxygen criteria are described in §
307.7(b)(3)
of this title (relating to Site-Specific Uses and Criteria).
(2) Aquatic life use categories and dissolved
oxygen criteria for classified segments are specified in Appendix A of §
307.10 of this
title. Aquatic life use categories and dissolved oxygen criteria for other
specific water bodies are specified in Appendix D of §
307.10 of this
title. Where justified by sufficient site-specific information, dissolved
oxygen criteria that differ from §
307.7(b)(3)
of this title may be adopted for a particular water body in §
307.10 of this
title.
(3) Perennial streams,
rivers, lakes, bays, estuaries, and other appropriate perennial waters that are
not specifically listed in Appendix A or D of §
307.10 of this
title are presumed to have a high aquatic life use and corresponding dissolved
oxygen criteria. Applicable dissolved oxygen criteria are described in §
307.7(b)(3)(A)
of this title. Higher uses are protected where they are attainable.
(4) When water is present in the streambed of
intermittent streams, a 24-hour dissolved oxygen mean of at least 2.0 mg/L and
24-hour minimum dissolved oxygen concentration of 1.5 mg/L must be maintained.
Intermittent streams that are not specifically listed in Appendix A or D of §
307.10 of this
title are considered to have a minimal aquatic life use except as indicated
below in this subsection. For intermittent streams with seasonal aquatic life
uses, dissolved oxygen concentrations commensurate with the aquatic life uses
must be maintained during the seasons when the aquatic life uses occur.
Unclassified intermittent streams with perennial pools are presumed to have a
limited aquatic life use and corresponding dissolved oxygen criteria. Higher
uses are protected where they are attainable.
(i) Aquatic life uses and habitat. Vegetative
and physical components of the aquatic environment must be maintained or
mitigated to protect aquatic life uses. Procedures to protect habitat in
permits for dredge and fill are specified in Federal Clean Water Act, §404 and
in Chapter 279 of this title (relating to Water Quality
Certification).
(j) Aquatic
recreation.
(1) Existing, designated,
presumed, and attainable uses of aquatic recreation must be maintained, as
determined by criteria that indicate the potential presence of pathogens.
Categories of recreation and applicable criteria are established in §
307.7(b)(1)
of this title.
(2) Recreational use
categories and criteria for classified segments are specified in Appendix A of
§
307.10 of this
title. Site-specific recreational use categories and criteria for selected
unclassified water bodies are specified in Appendix G of §
307.10 of this
title. Where justified by sufficient site-specific information, recreational
uses and criteria that differ from §
307.7(b)(1)
of this title may be adopted for a particular water body in §
307.10 of this
title. For water bodies not specifically listed in Appendix A or Appendix G of
§
307.10 of this
title, the following recreational uses are presumed to apply.
(A) Primary contact recreation 1. Primary
contact recreation 1 is presumed for lakes, reservoirs, and tidal water bodies.
Primary contact recreation 1 is presumed to apply to intermittent streams,
intermittent streams with perennial pools, nontidal wetlands, and perennial
freshwater streams and rivers, except where site-specific information indicates
that recreational activities that involve a significant risk of ingestion have
little to no likelihood of occurring, in accordance with subparagraph (C) of
this paragraph.
(B) Primary contact
recreation 2. No water body is presumed to have a use of primary contact
recreation 2. This use is applicable when designated for an individual water
body as listed in Appendix A or G in §
307.10 of this
title. Primary contact recreation 2 applies to water bodies where water
recreation activities that involve a significant risk of ingestion of water
occur, but less frequently than for primary contact recreation 1 due to:
(i) physical characteristics of the water
body; or
(ii) limited public
access.
(C) Secondary
contact recreation 1. Secondary contact recreation 1 applies to water bodies
where water recreation can occur, but the nature of the recreation does not
involve a significant risk of ingestion. Secondary contact recreation 1 applies
to intermittent and perennial freshwaters where site-specific information
demonstrates that primary contact recreation 1 or 2 have little to no
likelihood of occurring. At a minimum, the following characteristics must be
demonstrated for a presumed use of secondary contact recreation 1 to apply:
(i) during dry weather flows, the average
depth at the thalweg (mid-channel) is less than 0.5 meters and there are not
substantial pools with a depth of 1 meter or greater; and
(ii) there are no existing recreational
activities that create a significant risk of ingestion or uses for primary
contact recreation 1 or 2.
(D) Secondary contact recreation 2. Secondary
contact recreation 2 applies to water bodies where water recreation activities
do not involve a significant risk of water ingestion and where activities occur
less frequently than for secondary contact recreation 1 due to physical
characteristics of the water body or limited public access. No water body is
presumed to have a use of secondary contact recreation 2. This use is
applicable when designated for an individual water body as listed in Appendix A
or G in §
307.10 of this
title.
(E) Noncontact recreation.
Noncontact recreation applies to water bodies where recreation activities do
not involve a significant risk of water ingestion and where primary and
secondary contact recreation uses should not occur because of unsafe
conditions. No water body is presumed to have a use of noncontact recreation.
This use is applicable when designated for an individual water body as listed
in Appendix A or G in §
307.10 of this
title.
(3) Assigning
recreational uses to an unclassified water body.
(A) Applying presumed uses. Recreational uses
and associated numerical criteria are assigned to an unclassified water body in
accordance with the presumed uses and guidelines established in paragraph (2)
of this subsection. To assign uses other than primary contact recreation 1, a
reasonable level of inquiry is conducted to determine if a different presumed
use is appropriate for a particular water body. A reasonable level of inquiry
includes review of available relevant information or completed site
surveys.
(B) Assigning presumed
uses. Presumed uses of primary contact recreation 1 and secondary contact
recreation 1 can be assigned to an individual water body for regulatory action
without individually designating the recreational use and criteria in Appendix
G in §
307.10 of this
title. Regulatory action may include issuing Texas Pollutant Discharge
Elimination System permits, revising the list of impaired water bodies under
federal Clean Water Act, §303(d), or setting and implementing a total maximum
daily load. The presumed secondary contact recreation 1 use is included in the
public notice of a regulatory action that could affect recreational water
quality, and the assigned recreational uses are subject to applicable public
comment and approval by the United States Environmental Protection Agency
(EPA). For tracking purposes, presumed recreational uses that have been
determined to be less stringent than primary contact recreation 1 are noted in
a publicly available list such as the EPA's Water Quality Standards Repository
prior to a water quality standards revision. Presumed uses that have been
determined for particular water bodies are listed in Appendix G in §
307.10 of this
title when the water quality standards are revised.
(C) Assigning a use less stringent than
presumed use. A recreational use that is less stringent than the applicable
presumed use can only be assigned to an individual water body for a regulatory
action after that use is approved by the EPA and designated in Appendix A or G
in §
307.10 of this
title. Support for designating a use less stringent than an applicable presumed
use requires a use-attainability analysis (UAA). 40 Code of Federal Regulations
§131.10(g) lists six reasons for a change in use in a water body. At least one
of these reasons must be included in the UAA.
(k) Antidegradation. Nothing in this section
is intended to be construed or otherwise used to supersede the requirements of
§
307.5
of this title (relating to Antidegradation).
(l) Assessment of unclassified waters for
aquatic life uses. Waters that are not specifically listed in Appendices A or D
of §
307.10 of this
title are assigned the specific uses that are attainable or characteristic of
those waters. Upon administrative or regulatory action by the commission that
affects a particular unclassified water body, the characteristics of the
affected water body must be reviewed by the commission to determine which
aquatic life uses are appropriate. Additional uses so determined must be
indicated in public notices for discharge applications. Uses that are not
applicable throughout the year in a particular unclassified water body are
assigned and protected for the seasons where such uses are attainable. Initial
determinations of use are considered preliminary, and in no way preclude
redeterminations of use in public hearings conducted under the provisions of
the Texas Water Code. For unclassified waters where the presumed minimum uses
or criteria specified in this section are inappropriate, site-specific
standards may be developed in accordance with §
307.2(d)
of this title (relating to Description of Standards). Uses and criteria are
assigned in accordance with this section and with §
307.7(b)(3)
of this title. Procedures for assigning uses and criteria are described in the
standards implementation procedures.
(m) pH. Consistent with §
307.1 of
this title, pH levels in all surface water in the state must be maintained so
as to not interfere with the reasonable use of such waters.
